Through the years, many people have participated in maintaining various types of birds within their dwellings for purposes of amusement and pleasure. In the typical bird environment, a small cage is maintained within which the birds are secured and housed. Among the food preparations provided by bird keepers for their pet birds, the most common is a mixture of various seeds and small grains which form the staple of the pet birds.
In the majority of seeds and small grains used for bird seed mixture, a problem arises in the presence of the outer hull material of the seed separate from the seed itself. Since typically such bird seed mixtures are purchased in bulk and comprise a mixture of various sizes of seed, the presence of the undesired hull materials is an annoyance and source of difficulty for the bird keeper. The problem is exacerbated by the tendency of seed hulls to break off and separate during shipping and handling of the seed mixture. As a result, the typical seed mixture product obtained by the bird keeper is often undesirably mixed with empty hulls. Since small quantities of seed mixture are dispensed to the receptacles within the bird cage, the presence of excessive seed hulls within the mixture dilute the amount of nutritious seed mixture given to the pet birds at any given feeding.
A similar problem arises in the food industries which process, store and transport grain and other similar materials. To meet this need, a number of devices have been developed through the years which provide a separation of the hull materials from the remainder of the grain. In general, such mechanisms differ substantially in construction details and operational subtleties but typically make use of an air flow to achieve separation. The use of air flow to separate the heavier grains from the lighter hull materials is well known and originates in the ancient agricultural process in which quantities of grain and hull material were simply thrown into the air on windy days. The wind passing through the airborne mixture of grain and hull material carried the lighter hull material away but had little effect upon the heavier grain. Thus, the grain material, relatively free of the lighter hulls, accumulated on the ground while the hulls and other light materials were blown to a separate pile.
One example of such air separators is set forth in U.S. Pat. No. 2,828,011 issued to Whitby which sets forth a STRATIFIER AND AIR SEPARATOR in which a quantity of mixed particles of material are caused to be dropped through an area in which they are subjected to a cross flow of air. A plurality of collecting bins are supported beneath the material flow for collection of the material. The principle of operation relies upon the different weights of the particles to produce stratified downward flow of the materials and thereby separate them from each other.
U.S. Pat. No. 775,965 issued to Edison sets forth a DRY SEPARATOR in which a blower produces a flow of air through a large passage. The passage defines an upper aperture through which a quantity of to-be-separated material is introduced to the air flow. The bottom portion of the air passage includes a pair of collecting baffles spaced apart with one upstream of the other in the air flow. In operation, a granular material such as a mixture of free gold and loose gravel is dropped through the air flow and the heavier gold material accumulates in the upstream baffle while the lighter gravel accumulates in the downstream baffle.
U.S. Pat. No. 1,042,836 issued to Stromborg sets forth a SEPARATOR in which a large plenum is provided with an aperture and chute through which the to-be-separated material is introduced to the plenum. The plenum supports a plurality of directing baffle members as well as a plurality of collecting bins. The bins are arranged in a serial arrangement in the direction of air flow. A blower mechanism is coupled to the plenum and provides a flow of air through the plenum. In operation, the to-be-separated material is introduced to the plenum through the upper chute and is affected by the transverse air flow through the plenum in accordance with the baffle orientation. The heavier materials accumulate in the more upstream bins while the lighter materials are deflected and collected in the downstream bins.
U.S. Pat. No. 764,478 issued to Lewis sets forth a GRAIN SEPARATOR in which a quantity of material is accumulated in a hopper and poured through a bottom aperture to provide a downward flow of the material. A rotating paddle wheel is supported beneath the hopper and receives the downward flow of material. The rotating paddle wheel causes the heavier particles to be deflected or thrown a different distance than the lighter particles. In addition, a fan mechanism is provided to direct an air flow transversely across the material to assist in the separation process.
U.S. Pat. No. 3,384,233 issued to Bolles sets forth a PROCESS AND APPARATUS FOR DRY-CLEANING SUGAR CANE in which a quantity of harvested sugar cane and associated leaves and other lighter materials are accumulated in a hopper. The hopper includes a conveyor belt mechanism which transfers the material to a rotating paddle wheel. The rotating paddle wheel carries the composite material from the hopper and throws it downwardly in a stream of falling material. A blower mechanism provides a transverse air flow to the falling materials which deflects the lighter leaves and other materials from the heavier sugar cane and produces a separation of the cane material from the remainder of the mixture. The heavier cane material falls downwardly for collection in one area of the separator while the lighter deflected materials are accumulated elsewhere.
While the foregoing described air separating devices have achieved some success in the particular uses for which they have been conceived, they are mass production devices which do not readily lend themselves to the convenient processing of small quantities of bird seed mixture. There arises and remains, therefore, a need in the art for a small compact portable and inexpensive hull separator which may be maintained and used by individual bird owners.